[Diagnosis of acute phase of venous infarction by diffusion-weighted image: case report and review of the literature].

Diffusion-weighted imaging (DWI) can diagnose early stage not only of the arterial infarction but also of venous infarction. We successfully diagnosed a case as acute venous infarction by DWI. The patient, an infant of one year and ten months, presented disturbance of consciousness and left hemiparesis two weeks after dehydration and infections. Computed tomographic scan revealed a cerebral hemorrhage in the right parietal lobe. Cerebral angiography revealed no contrast filling of the posterior side of superior sagittal sinus, straight sinus and transverse sinus. DWI demonstrated a large hyperintensity lesion around the hematoma, suggesting venous infarction in the early stage. We thought that venous infarction was caused by secondary extension of thrombus to cerebral cortical veins and deep cerebral veins. External decompression and postoperative hypothermia therapy were performed because of rapidly deteriorating intracranial hypertension. Intracranial hypertension was, however, uncontrollable. The patient died four days after the onset. Diagnosis of the venous infarction by DWI was discussed along with other recent reports. Diffusion hyperintensity was displayed in almost all subjects with acute venous infarction. DWI pattern of venous infarction is more heterogeneous than that of arterial one because pathway from venous obstruction to infarction is complicated.

Sigmoid sinus thrombosis after mild closed head injury in an infant: diagnosis by magnetic resonance imaging in the acute phase--case report.

Intracranial sinus thrombosis following a mild closed head injury without a skull fracture or intracranial hematoma is extremely rare. A 23-month-old girl presented with vomiting and gait ataxia 1 day after occipital trauma. Computed tomography revealed a slightly increased density area in the region of the left sigmoid sinus. T1-weighted magnetic resonance (MR) imaging demonstrated an isointense area in the left sigmoid sinus and T2-weighted imaging showed a hyperintense area reflecting the characteristics of oxyhemoglobin. MR angiography and cerebral angiography indicated occlusion of the left sigmoid sinus. After 4 days of conservative treatment, her symptoms subsided completely. Follow-up MR angiography and cerebral angiography showed recanalization of the sigmoid sinus. The MR images and MR angiograms were useful for both early diagnosis and follow-up. Treatment should reflect the severity of individual cases, and early diagnosis will help achieve a good outcome.